Outgassing Filtering System for a Luminaire

The disclosure generally relates to luminaires, and more specifically to a system and method for removing contamination from the air in a closed compartment of a luminaire.

Luminaires with automated and remotely controllable functionality (which may be referred to as automated luminaires) are well known in the entertainment and architectural lighting markets. Such products are commonly used in theatres, television studios, concerts, theme parks, night clubs, and other venues. A typical automated luminaire provides control from a remote location of the pan and tilt functions of the luminaire allowing an operator to control the direction the luminaire is pointing and thus the position of the light beam on the stage or in the studio. Many automated luminaires additionally or alternatively provide control from the remote location of other parameters such as intensity, focus, zoom, beam size, beam shape, and/or beam pattern of light beam(s) emitted from the luminaire. Some automated luminaire products may be designed for outdoors in, for example, theme parks or concerts. Such luminaires may be designed to maintain a dry, controlled physical environment inside the luminaire.

In a first embodiment, a luminaire includes a head having a housing. The head includes a light source that generates heat; one or more motors that generate heat; one or more lubricated surfaces that, when heated, release airborne contaminants; one or more painted surfaces that, when heated, release airborne contaminants; a plurality of lenses; and an adsorptive filter system configured to reduce airborne contaminants in air contacting one or more lenses of the plurality of lenses by pulling contaminated air through the filter system and directing filtered air onto the plurality of lenses.

Preferred embodiments are illustrated in the figures, like numerals being used to refer to like and corresponding parts of the various drawings.

Luminaires may contain materials which can outgas, particularly when heated. For example, plastics, adhesives, and paints may release airborne contaminants including VOCs (Volatile Organic Compounds) when they are heated. In addition, luminaires may contain electronics and circuit boards whose packaging and other materials outgas. Further, motors (such as stepper motors), bearings, linear slides, and other lubricated surfaces may also outgas. Heat from a light source in the luminaire may be a primary source of heat that may trigger outgassing. However, stepper motors also generate heat internally during normal operation, and may also be significant producers of contaminants, even when the light source itself is turned off.

Such outgassed airborne contaminants may re-condense or be otherwise deposited (for example, by contaminant particles contacting and attaching to a surface) on surfaces within the luminaire, including on lenses and/or other optical elements of the luminaire, through which a light beam generated by the light source passes before exiting the luminaire. Such condensation and/or deposition may gradually accumulate as a film coating on those components. Such a film may diffuse the light passing through the optical elements, possibly resulting in a hazy light output, which may have haloes around the emitted light beam. One remedy to such a problem may be for the user to open the luminaire and clean surfaces of the optical elements, in order to regain the original sharp light output. However, the hazy coating may reappear quickly as the luminaire is used and outgassing continues.

The problem is likely exacerbated with luminaires intended for outdoor use which may be sealed and water tight. In such products the outgassed contaminants have no route to exit the luminaire and end up condensing and/or depositing on internal surfaces.

Some systems may attempt to solve the problem of outgassing by using heaters and directed air flow to attempt to prevent outgassed contaminants from condensing on optical surfaces. However, such solutions only attempt to direct airborne contaminants away from optical elements and don't actually remove the contaminants from the air inside the luminaire. Furthermore, once such a luminaire is powered down, such heating and air flow may cease, allowing contaminants to condense and/or deposit on the optical elements.

Systems according to the disclosure reduce deposition of contaminants from the air inside the luminaire on optical elements of the luminaire by pulling contaminated air through an adsorptive filter system and directing the filtered air onto on lenses and/or other optical elements of the luminaire.

1 FIG. 100 100 102 120 124 102 104 104 102 120 126 122 122 124 presents an orthogonal view of a luminairecomprising an outgassing filtering system according to the disclosure. The luminaireis a luminaire comprising a headwhich is configured to rotate within a yokeabout a tilt axis. The headcomprises a housing. In some embodiments, the housingis configured to make the headwaterproof. The yokeis configured to rotate relative to a fixed enclosureabout a pan axis. The pan axisand the tilt axisare orthogonal to each other. Both pan and tilt motions may be mechanically coupled to hand-operated manual controls or may be coupled for motion to motors, linear actuators, or other electromechanically controlled mechanisms.

100 110 100 110 112 100 110 112 100 110 102 100 102 122 124 Such electromechanical mechanisms and other components of the luminairemay be under the control of a control system(e.g., a microcontroller or other programmable processing system) included in the luminaire. In some embodiments, the control systemmay communicate with a user and be controlled locally via a user interfaceincluded in the luminaire. In such embodiments, the control systemmay display information to the user on a display screen of the user interface. Such information may relate to a status of a component of the luminaire. In other embodiments, the control systemmay be in wired or wireless communication via a data link with a remotely located control console that an operator uses to indicate a desired position of the head. In such embodiments, the operator is able to direct light output from the luminairein a desired direction, through motion of the headin the pan axisand tilt axis.

2 FIG. 1 FIG. 2 FIG. 102 100 104 102 102 102 102 202 204 206 presents an orthogonal view of the headof the luminaireofwith the housingremoved to show internal components of the head. In the orientation shown in, the left end of the headmay be referred to as the rear and the right end of the headreferred to as the front. The headcomprises a light source, optical components, and a zoom optical system comprising a plurality of lenses.

102 102 208 206 102 208 206 208 100 206 208 208 206 As described above, the internal components of the headmay comprise materials that can outgas, such as lubricants, plastics, adhesives, and paints that may release airborne contaminants including VOCs when heated. To reduce the amount of such airborne contaminants, the headfurther comprises an adsorptive filter system, configured to reduce airborne contaminants in air that contacts one or more lenses of the plurality of lensesby pulling contaminated air from rearward portions of the headthrough the adsorptive filter systemand directing the resulting filtered air onto the plurality of lenses. The adsorptive filter systemis mounted in the luminairein a position that reduces the amount of contaminated air pulled across the plurality of lensesinto the adsorptive filter system. Baffles and bulkheads that are used to mount the adsorptive filter systemmay also reduce the amount of contaminated air that is pulled across the plurality of lenses.

3 FIG. 4 FIG. 3 FIG. 208 208 402 208 208 302 402 206 presents an orthogonal view of the adsorptive filter systemaccording to the disclosure. As will be explained in more detail with reference to, a bottom portion of the adsorptive filter system(as oriented in) comprises fansthat pull contaminated air through the adsorptive filter systemand expel filtered air. The adsorptive filter systemcomprises a bafflethat deflects the filtered air expelled from the fansonto the plurality of lenses.

2 FIG. 102 210 210 110 110 402 210 110 402 208 210 Returning to, in some embodiments, the headincludes a sensorconfigured to sense airborne contaminants within the housing and to produce a signal related to an amount of airborne contaminants sensed. In such embodiments, the sensoris electrically coupled to the control systemand the control systemis configured to control a speed of fansbased on the signal produced by the sensor. In one example, the control systemcauses the fansto pull more air through the adsorptive filter systemwhen the signal produced by the sensorindicates a higher amount of airborne contaminants in the housing.

4 FIG. 3 FIG. 208 208 402 406 408 402 403 404 402 403 406 408 404 presents an exploded view of the adsorptive filter systemof. The adsorptive filter systemcomprises two fans, two associated cup-shaped containers, and a cover. Each fancomprises an air intakeand an air outlet. Each fanis configured to pull air into its air intakethrough its associated cup-shaped containerand the coverand to expel air from its air outlet

406 406 410 406 406 402 410 408 406 410 4 FIG. 4 FIG. Each cup-shaped containeris configured to contain activated charcoal pellets and has a cylindrical wall, an open first end at its top, and a closed second end at its bottom, in the orientation shown in. The activated charcoal pellets are not shown inin order to more clearly show the structure of the cup-shaped containers. The closed second end comprises a protrusionextending into an interior of the cup-shaped container. The closed second end of the cup-shaped containeris thus configured to couple to its associated fan. The protrusionand the cylindrical wall comprise openings that are configured to allow passage of air and prevent passage of the activated charcoal pellets. The coveralso comprises openings that are configured to allow passage of air and prevent passage of the activated charcoal pellets. Each cup-shaped containeris thus configured to contain its activated charcoal pellets in an inverted cup shape, improving airflow between the cylindrical wall and the protrusion.

3 4 FIGS.and 3 4 FIGS.and 402 406 402 406 408 406 408 406 While the embodiment ofcomprises two fansand two cup-shaped containers, other embodiments may comprise more or fewer than two fansand two cup-shaped containers. Similarly, while the embodiment ofcomprises a single coverfor the two cup-shaped containers, other embodiments may comprise two covers, one for each of the two cup-shaped containers.

406 412 406 412 110 110 112 110 112 In some embodiments, one of the cup-shaped containersincludes a sensorconfigured to sense a contaminant saturation of the activated charcoal pellets in the cup-shaped containerand to produce a signal related to an amount of contaminant saturation sensed in the activated charcoal pellets. In such embodiments, the sensoris electrically coupled to the control systemand the control systemis configured to compare the signal to a threshold value and display on the user interfaceinformation relating to a result of the comparison. In one example, if the signal is above the threshold value, the control systemdisplays information on the user interfaceindicating that the activated charcoal pellets are excessively contaminated and require replacement.

While only some embodiments of the disclosure have been described herein, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the disclosure herein. While the disclosure has been described in detail, it should be understood that various changes, substitutions, and alterations can be made hereto without departing from the spirit and scope of the disclosure.